Classic Restore

[blusnowkitty]

Right - I did look them up and provided what I think is a valid option - but the comment "crazily tiny" are what worry me. I'm not an EE - I don't know what I don't know I'm learning and want to know more!

Grab a set of calipers ($20 at Harbor Freight - https://www.harborfreight.com/6-in-digital-caliper-63711.html ) and measure the diameter of the original capacitor, then try and find something similar to that.

 

[LaPorta]

Yes that’s how I got my original measurements. But for now just see the measurements of the parts that are on the list and look for similar.

 

[erichelgeson]

I really do appreciate the guidance. I personally feel uncomfortable with my current knowledge to pick exactly what I need. I ended up going with a Console5 kit as it's the easy way out (found they list all the exact info on their wiki pages). And honestly the price was within $2. I'm glad I went through everything as detailed as I did as now I have a map out of every part, value, etc for when the parts come. Now we play the waiting for capacitors game.

 

[ScutBoy]

I really do appreciate the guidance. I personally feel uncomfortable with my current knowledge to pick exactly what I need. I ended up going with a Console5 kit as it's the easy way out (found they list all the exact info on their wiki pages). And honestly the price was within $2. I'm glad I went through everything as detailed as I did as now I have a map out of every part, value, etc for when the parts come. Now we play the waiting for capacitors game.

I've been using the Console5 kits lately and have been happy with them. Its mostly a convenience thing, since like you I get overwhelmed by trying to find the right parts at DigiKey or Mouser.

Plus, you get an Atomic Fireball in the box with your order

 

[erichelgeson]

Caps came yesterday - did the logic board today and tested it in my working Classic II - wish more Macs came with bootable rom.

The recap went well, always one joint I dont like and have to retouch.

First boot it gave me a checkerd screen, then rebooted a few times in a row, then was fine. Subsequent reboots had no issue.

Analog board will be tonight or tomorrow.

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[cheesestraws]

wish more Macs came with bootable rom

Yes!  The boot-from-ROM is one of the reasons the Classic is one of my favourite machines

 

[bibilit]

Not necessarily – the power connectors on the physical AB are different. But the power connectors that plug into other boards are compatible between the Classic and Classic II – after all, you can upgrade a Classic to a Classic II by swapping the logic board.

Not really, if you are just trying to swap AB boards, that won’t work due to different connectors. 

But if you remove the yoke from the CRT as well, or the complete screen assembly, all will be fine. 

Pretty sure a small adapter from A to B connectors can be hacked easily for testing purposes. 

 

[erichelgeson]

Analog board recapped, always triple check, had one marked down wrong (luckily noticed before we started)

Still the same issue of needing to be "warm" to boot & for the waves to go away.

Anyone have suggestions on what component might need to be "warmed" up to be replaced?

Thanks!

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[erichelgeson]

Soap, water, magic eraser and it's now "clean" - removing the stickers you can see the original color. The front actuallyd came out quite nicely and not yellowed much. Took a few minor spots of rust off and cleaned the inside too.

If anyone has ideas on my "needs warming up" recapped PSU I'm all ears.

Will be trying some retro bright on the back cover next week as it's so discolored.

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[cheesestraws]

If anyone has ideas on my "needs warming up" recapped PSU I'm all ears.

You might have more luck troubleshooting with a freeze spray type thing; wait for it to warm up and start something running, then cool down bits of the board (reasonably carefully!) and see when it falls over. 

 

[erichelgeson]

freeze spray

Good call, have seen this done before but I haven't tried it.

Found a thread on a similar problem from 2019 though it never wraps up - just goes off topic on WD-40 http://www.vcfed.org/forum/showthread.php?68426-Mac-Classic-Analog-Board-Low-Voltage-Problems

Has a few things to try though.

Edit: Reading through chapter 9 here - a ton of things to try http://www.maccaps.com/MacCaps/Repair_books_files/Mac Classic %26 SE Repair and Upgrade Secrets.pdf

 

[LaPorta]

What retrobrite method will you be using?

 

[erichelgeson]

What retrobrite method will you be using?

12% hair product (thought it was 40%, but the label was misleading!) and oxi - the "classic" method I suppose. Still a bit of reading to do. I've done the sun only with good success, but this one is quite yellowed.

 

[LaPorta]

How much oxy with how much water? I am going to do similar with oxy only and am not sure how much to mix up.

 

[erichelgeson]

I've solved the Analog board issue!

After reading both links above I looked at my board again. There was a lot more electrolytes on the bottom side than I thought - it's not the normal "shiny grime" - more of a slight discoloration - and there was so much of it i honestly thought it was just the normal color of the PCB! I scrubbed a lot with 99% IPA between each contact that i thought could be a bridge and used a tooth pick to clean crust off. Focusing on LL1/LL2 and the other major components. I did note there is quite a bit of yellowing of traces that probably got too hot at one point.

I also gave PP1 a twist and clean. Turned it on adjusted till I had stable 5v & 12v.

Boots straight up, no checker, no loops, no waves! Huzza!

Don't underestimate how dirty these board can get with 25 leaky caps.

Tested with load and it's stable @ 11.98v, 4.98v, -11.98

 

[erichelgeson]

oxy with how much water

Not quite sure yet heading out on vacation tomorrow so will be doing some reading thinking on it. Will let you know what I choose.

 

[dochilli]

Someone told me that he used 2-3 spoon oxi for about 10 litres of water, but he used hot, nearly boiling water! Did not try it up to now, but I will do that in 3 weeks.

 

[erichelgeson]

Quite happy with the results, I kept the cover off to compare. Used 64oz of 3% peroxide, few table spoons of oxy, in a clear plastic storage bin, with a few landscaping  rocks to take up volume inside and the rest filled with water. No streaking at - the slight variation on the picture is just water I wiped away before taking the pic.

Front, keyboard, and back panel are in waiting for the sun tomorrow.

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[erichelgeson]

TIL the screws for the screen are a different length. Just had a pile of them and grabbed the wrong one, went in a bit hard but backed out, compared to another (wrong one) and thought maybe the plastic was stripped on the inside. I was wrong. Pretty disheartening since this is really not repairable after repairing everything else. Ugh.

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[markyb86]

You can sand that screw hole down, use some JB Weld "SteelStik" (an epoxy putty that dries white-ish gray, or use something similar)

smash the putty into the hole, and then make a flat & textured surface on the front by pressing the battery cover into it, or a foam sponge.  It's such a small ding that it shouldn't be so bad to repair like that.

https://www.jbweld.com/product/steelstik-epoxy-putty-stick